Posted
by
Unknown Lamer
on Tuesday September 25, 2012 @02:56PM
from the do-the-dew dept.

The Bad Astronomer writes "Astronomers have unveiled what may be the deepest image of the Universe ever created: the Hubble Extreme Deep Field, a 2 million second exposure that reveals galaxies over 13 billion light years away. The faintest galaxies in the images are at magnitude 31, or one-ten-billionth as bright as the faintest object your naked eye can detect. Some are seen as they were when they were only 500 million years old."

I'm not sure whether to be more impressed by:
1) the scale of the universe itself
2) the ability of some insignificant bags of protoplasm on an insignificant planet near a run of the mill star, in a less than impressive galaxy could find a way to actually see that far
3) the fact that they held the camera that steady for 2 million seconds (23 days)
4) That the camera moved 36 million miles during those 23 days and it didn't make any difference in the final image.

But other than that, the image looks exactly like a gazillion other images from Hubble, so one has to take it on faith that it is what it says it is.

Also consider that this image shows 5,500 or so galaxies in a tiny fraction of the sky. There are something like 100 billion galaxies in the known Universe and trillions upon trillions of stars (cue Carl Sagan). I'd say life on another planet isn't just a possibility, but a statistical certainty. Of course, finding/reaching/communicating with that life might be another matter entirely.

2) Scientists continually marvel at the fact they are seeing the universe far away the way it was millions or billions of years ago.

3) I never hear them comment on the fact what they are seeing has changed as much as our near universe in all of that time.

SO... what's to say we're not looking at the beginnings of literally millions (+?) of civilizations that in a few million years would look to the Hubble like we do now from up close?

Astronomers spend SO much of their time looking at light-speed forced history that I feel a certain slight is paid to what the present truly may be. The universe may be absolutely teaming with life that we won't be able to even see the beginnings of in ours or even our great-great-great-great-...........-great-great-grandchildren's lifetimes.

Astronomers spend SO much of their time looking at light-speed forced history that I feel a certain slight is paid to what the present truly may be.

Time is not universal. Across these distances, you can't just take our local clock and apply it to some remote location. Your question of "What is happening 13 light-years away simultaneously with what we consider the present?" just doesn't have an answer on its own. You need to define your point of observation. If you are using us as your observer, then what you see through the telescope is what you get. That's your present day reality.

You can't just "decide to master faster than light travel" because it's probably not possible. See, as far as we can tell right now, any two of the following can coexist (but not all three): faster than light travel, relativity and causality. Relativity has been experimentally verified to the best of our ability and hasn't come up wrong yet, and if causality can be broken you can get all sorts of weird shenanigans and paradoxes happening. That's not to say it's 100% impossible that there are ways around tha

I'd say life on another planet isn't just a possibility, but a statistical certainty

I'd say that the liklihood of us being the only life is remote, but not certain. And if there is life out there, it may well be that we simply don't find it, because it was here long before us, long after we become extinct, or just too damned far away (which would be any galaxy except our own).

There may be something special about his rock. We just don't know. Until we find life elsewhere, there is no life elsewhere.

I don't know why that seems off to you. We're talking about extremely faint signals with absolutely terrible signal-to-noise ratios. It takes a huge amount of data to generate enough parity to resolve what's signal and what's noise. To be honest, I'm surprised this wasn't one of hubble's first missions.

The signal to noise ratio on the sensor inside the hubble. There is inherent noise from the electronics on the sensor. The more you amplify your signals, the more you amplify noise. Study CCD sensors. You'll find the reason that they had to stack this exposure 2000 times. The noise is random, so you can average it out with multiple exposures. Looks like they did a 15-16 minute exposure here.

2 million seconds is 33,333 minutes which is 555 hours which is 23 days. You mean they took an exposure for 23 days to get this image?

I'm not saying it can't be done, only that this seems a bit off.

Stacking. You can do this at home with a little scope and a CCD. Obviously this is an art requiring extensive signal processing expertise.

I'm guessing off the top of my head its a heck of a lot more like 3000 ten minute exposures stacked up. And probably a heck of a lot of rounding (like not 2 million but precisely 1834101.2352 seconds). So if you get an orbit every two hours, and each orbit you grabbed data for 10 mins, it would take like a year to gather the data and then stack em up.

Silly me I forgot to mention why you stack instead of stare.If you stare then looking at the physics of a CCD imager the photon, err, its resulting charge, that arrived 10% of the way thru the exposure, is going to start leaking thru the gate insulator. So is a digital result of 12345 equivalent to 12345 photons arriving the instant before you read the array out, or 98765 photons a long time ago that leaked outta the array? But if you take nice short exposures you don't have that issue.

I think it takes way longer than that. If I remember correctly they open the shutter for a few minutes at a particular point in the telescope's orbit and catch a few photons. They then repeat this process every time the telescope swings around to that same spot, i.e. they can't just open the shutter for 2 million seconds otherwise there would just be a big smear of light. They actually add up small bit of a few seconds at a time, so it probably took more like months or maybe even years.

...it's full of stars! OK so I used the tagline from a movie. But then it is cool to see this stuff so far away while most of us mortals toil in our cubicles. Almost unreal like it's Photoshop (SETIcon II had panel discussion and one topic debated are difficult to tell actual images from CGI. Hint: don't process the raw images from scopes and spacecraft).

"We succeeded in taking that picture [from deep space], and, if you look at it, you see a dot. That's here. That's home. That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, e

The problem with coming to conclusions before you have evidence is that you'll start fitting the evidence into your conclusion. How about you don't assume what we are looking at and simply take it in as it comes?

Think about this for a moment: if in one of those galaxies in the further side of time and space, and intelligent species pointed a Hubble-like telescope to us, even if the telescope were sensible enough... they wouldn't see not a single, not even remotely meaningful signal, if only for the reason that they would be looking about 9 billion years too early.

The amount of time that intelligent critters who can manipulate tools and create recognizable radio signals for communication is likely to be very brief. In less than a century, data compression and encryption will make almost all of our radio traffic look like static from the outside. The vaguely intelligible bits sent out prior to that are so weak that they'll likely never be received or interpreted. Bottom line? Lack of intelligent radio indicates nothing.

The amount of time that intelligent critters who can manipulate tools and create recognizable radio signals for communication is likely to be very brief. In less than a century, data compression and encryption will make almost all of our radio traffic look like static from the outside. The vaguely intelligible bits sent out prior to that are so weak that they'll likely never be received or interpreted. Bottom line? Lack of intelligent radio indicates nothing.

Jupiter's natural radio emissions are much more powerful than the total of all Earth-based signals. Even if one was looking for radio signals from our system, we wouldn't be the loudest voice.

Still you'd think that with so many stars to choose from, we'd expect to get more then a few vaguely human-like alien species.

I rather prefer the explanation that the radio-age doesn't last long enough - less then 200 years into it and we're already heading out of it. If there's a breakthrough or new physics around the corner, then it might be over completely if you can do things with entangled particles - and as you say, all the leaky intelligible stuff is being replaced with tight-beam radio and encryptio

I find our current method of radio communication extremely inefficient. A signal much stronger than necessary for a decent antenna and signal processor is broadcast in all directions hoping to be heard by one or many devices. It's the electromagnetic equivalent of everyone shouting straight up in the air whether they are talking to their neighbor or the guys over the hill. A properly calibrated signal isn't heard much beyond the intended recipient. I expect that a much better form of communication will be d

I'm curious about the statement that some we are seeing around 500M y.o. Can someone tell me what that is based upon? I'm not up on the latest numbers but I thought the universe was to be approx 14B y.o. Does it take into account increasing expansion of space over that period? Does it assume we are at the furthest point away from those other galaxies (or are they saying it only extends 500M light years beyond us)? I understood all of it except that side comment./noob question.

I'm curious about the statement that some we are seeing around 500M y.o. Can someone tell me what that is based upon?

How'd they do it? Donno. Maybe just assumptions based on redshift, maybe something else.

How would I do it? Wikipedia for metallicity. If it takes 14 billion years to nucleosynthesize this much carbon and stuff here in our galaxy, then if you see about 1/28th as much carbon and stuff over there then its probably only 1/28th the age or 500 Myr old.

They're calculating this based on the redshift, which has a remarkable correlation with distance. Another method of estimating distance is by angular size. The assumption that redshift of distant objects indicates they are moving away at near light-speed, along with the assumption that matter cannot travel faster than light, are the basis for the Big Bang Theory. These images are a strong counter-argument to that theory, because mature galaxies should not have existed at that time.http://bigbangneverhappene [bigbangneverhappened.org]

These images are a strong counter-argument to that theory, because mature galaxies should not have existed at that time.

Says who? Current theory places initial star formation at 400 million years after the Big Bang. Many of these initial stars were far more massive than any currently extant stars and had much shorter life-cycles, meaning galactic evolution happened quite quickly compared to the current pace.

If our universe is 14.5 Billion years old, and these galaxies we see are about 13 Billion light years away, shouldn't they be spread out much further apart? I would expect to only see a few galaxies in this picture.

Yup I dont get it either. From what I understand we are looking at things in different points in the past. So where is everything "today"?

Which makes me think of a question about the possibility of backwards time travel.

Say you invent a machine that takes you back in time. Since our planet, the Sun we orbit, the solar system and our Milky Way galaxy are all moving at 'X' mph, even if you did manage to go backwards (or forwards) In time, even for jusr a moment (ala H.G. Wells), wouldn't you just end up in space?

When I heard the learn'd astronomer;
When the proofs, the figures, were ranged in columns before me;
When I was shown the charts and the diagrams, to add, divide, and measure them;
When I, sitting, heard the astronomer, where he lectured with much applause in the lecture-
room,
How soon, unaccountable, I became tired and sick;
Till rising and gliding out, I wander'd off by myself,
In the mystical moist night-air, and from time to time,
Look'd up in perfect silence at the stars.

NASA's page about the eXtreme Deep Field [nasa.gov] has a picture showing the amount of sky photographed compared to the size of the moon. It looks like all 5500 galaxies could be covered up by a grain of sand held out at arms length.

Science doesn't promote itself. If there were any justice in the world, the Hubble team would be as celebrated as any sports team. This is certainly a much greater accomplishment than anything that happened at the Olympics. But that's not the world we live in. We need people like Phil Plait to publicly celebrate science. If there's a bit of self promotion in there too, so be it.

Jesus, you act like he's the Second Coming of Roland Piquepaille. Bad Astronomer's stuff is on-topic for the Slashdot crowd. A look back 13 billion years is interesting, and we count on guys like Bad Astronomer to bring it to our attention. Why don't you fuck off back to AOL or wherever it is you come from?

The fine even speckling is the CCD pixel resolution, you can ignore that, but the blue, red, green and other coloured specks that are not evenly spread are galaxies similtar to the prominent ones, just further out.